UV-ray sensitive composition and element for measuring UV-ray dose

ABSTRACT

PCT No. PCT/JP86/00572 Sec. 371 Date Jul. 8, 1987 Sec. 102(e) Date Jul. 8, 1987 PCT Filed Nov. 11, 1986 PCT Pub. No. WO87/03086 PCT Pub. Date May 21, 1987.A UV-ray sensitive composition, comprising a photo activator forming a free radical by the irradiation of UV-rays, a discoloring agent which exhibits a color change in visible region of spectrum through the action of this free radical, and a UV-ray absorber.

TECHNICAL FIELD

This invention relates to a UV-ray sensitive composition containing aphoto activator forming a free radical, a discoloring agent exhibiting acolor change in visible region of spectrum by the action of this freeradical, and a UV-ray absorber. This UV-ray sensitive composition canmeasure the irradiated dose of UV-rays, and therefore, the presentinvention also relates to an element, which can be easily produced andhandled, for measuring a UV-ray dose.

BACKGROUND ART

Sunburn is an acute dermatitis which occurs when sunlight, particularlyUV-rays, has been allowed to act excessively over the permissiblephysiological range of the skin, and is expressed as erythema (sunburn)and blackening (suntan). That is, although the intensity of the sunburnand the lapse thereafter will generally vary in accordance with thequantity and intensity of the UV-ray dosage generally acting on theskin, first a congestion of capillaries within the skin will occur,followed by erythema (sunburn) accompanied by edewa. After several days,the inflammation disappears, simultaneously with a disappearance of theerythema, and a melanin dye is deposited within the skin to cause ablackening (suntan) of the skin.

UV-rays are classified by wavelength, i.e., into a short wavelengthUV-ray region of 280 nm or lower (UV-C), a medium wavelength UV-rayregion of 280 to 320 nm (UV-B), and longer wavelength UV-ray region of320 to 400 nm (UV-A), but since UV-rays having a wavelength of 290 nm orlower are absorbed by the ozone layer in the atmosphere, and do notreach ground level, only the UV-rays having a wavelength of from 290 to400 nm (UV-B and UV-A) are biologically important. Namely, UV-rayshaving a wavelength of 290 to 320 nm (UV-B) are the primary cause ofacute erythema (sunburn), and are known as erythema region UV-rays, andUV-rays having a wavelength of 320 to 400 nm (UV-A) are known as theblackening region UV-rays, since these UV-rays promote blackening(suntan) of the skin.

In recent years, UV-ray absorbers, etc., have been developed and variouscosmetics for preventing sunburn of the human skin have been developedand are widely used. However, the intensity of UV-rays is greatlyinfluenced by the season, the time of day, and the weather, among otherfactors. Accordingly, as a counter-measure against sunburn, it isnecessary to measure the irradiated dose of UV-rays by a suitable andsimple means. Various methods for this measurement have been developedin the prior art. For example, dosimeters for determining an irradiateddose from fluorescent amounts or absorbance generated corresponding tothe irradiated dose when a UV-ray with a specific wavelength isirradiated, are known.

However, these prior art methods of measuring a UV-ray does requiregreat skill and a considerably long measurement time when measuring sucha dose, and the measuring devices concerned have a drawback in that theyare complicated and expensive.

In this connection, compositions which are discolored by the irradiationof UV-rays are disclosed in Japanese Patent Publication (Kokoku) No.40-17986 (photosensitive composition), Japanese Patent Publication(Kokoku) No. 44-22941 (photosensitive printing material), and JapaneseUnexamined Patent Publication (Kokai) No. 60-89352 (UV-ray discolorationsheet), among others, but all of these compositions undergodiscoloration by irradiation of UV-rays within an extremely short time,and therefore, although the presence of UV-rays can be determined by thecolor change, it is impossible to measure the irradiation dose ofUV-rays.

DISCLOSURE OF THE INVENTION

Accordingly, an object of the present invention is to provide a UV-raysensitive composition which undergoes discoloration corresponding to theirradiation dose of the UV-rays, and which can be easily produced andhandled, and is capable of simply measuring the irradiated dose ofUV-rays.

More specifically, according to the present invention, there is provideda UV-ray sensitive composition comprising a photo activator forming afree radical by UV-ray irradiation, a discoloring agent which exhibits acolor change in visible region of spectrum by the action of the freeradical, and a UV-ray absorber, and an element combined with such anagent for measurement of the UV-ray dose.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the present invention is described in detail byreferring to the drawings, wherein

FIG. 1 is a sectional view of a first embodiment of the element formeasurement of a UV-ray dose according to the present invention;

FIG. 2 is a sectional view of a preferred embodiment of the element formeasurement of a UV-ray dose shown in FIG. 1;

FIG. 3 is a sectional view of a second embodiment of the element formeasurement of a UV-ray dose according to the present invention; and,

FIG. 4 is a sectional view showing a preferred embodiment of the elementfor measurement of a UV-ray dose shown in FIG. 1.

PREFERRED EMBODIMENTS FOR CARRYING OUT THE INVENTION

The photo activator to be used in the composition of the presentinvention is known in this field of art, and representative examplesthereof may include, for example, the compounds represented by theformula (I):

    R--C--X                                                    (I)

(wherein, R represents allyl, alkyl, aralkyl, aroyl, alkenyl group,halogen, hydrogen, and X represents a halogen), such as carbontetrabromide, carbon tetrachloride, hexachloroethane, pentabromoethane,p-nitrobenzotribromide, bromotrichloromethane, hexabromoethane,benzotrichloride, iodoform, tetrachlorotetrahydronaphthalene, chloral,bromal, 1,1,1-tribromo-2-methyl-2-propanol, 1,1,2,2-tetrabromoethane,2,2,2-tribromoethanol, trichloroacetamide,1,1,1-trichloro-dimethyl-2-propanol, α,α,α-trichlorotoluene, etc.

As another photo activator, there are the compounds represented by theformula (II): ##STR1## (wherein Rx represents 1 to 5 substituents on abenzene ring, and specific examples of such substituents may include anitro group, halogen group, alkyl group, haloalkyl group, acetyl group,haloacetyl group, alkaryl group, alkoxy group, etc., and all of thesubstituents are not required to be the same), and specific examples ofsuch compounds may include o-nitro-α,α,α-tribromoacetophenone,m-nitro-α,α,α-tribromoacetophenone, p-nitro-α,α,α-tribromoacetophenone,α,α,α-tribromoacetophenone, α,α,α-m-tetrabromoacetophenone,α,α,α-tribromo-3,4-dichloroacetophenone,α,α,α-p-tetrabromo-acetophenone,α,α,α,α',α',α'-hexabromo-p-diacetylbenzene.

As still another photo activator, there are the compounds represented bythe formula (III):

    R--S--X                                                    (III)

(wherein R represents alkyl group, allyl group, allyl group havingsubstituent, and X represents a halogen), and specific example of suchcompounds may include 2,4-dinitrobenzenesulfenyl chloride,o-nitrobenzenesulfenyl chloride.

As still another photo activator, there are the compounds represented bythe formula (IV): ##STR2## (wherein A may be substituted with aheterocyclic compound residue, R¹, R² and R³ represent independently agroup selected from hydrogen, chlorine, bromine, etc., but all thereofcannot be hydrogens at the same time), and specific examples of suchcompounds may include ω,ω,ω-tribromoquinaldine, ω,ω-dibromoquinaldine,2-ω,ω,ω-tribromo-methyl-4-methylquinoline, ω,ω-dichloromethylquinoline,ω-bromolepidine, 2-ω-bromomethyl-isoquinoline,4-ω,ω,ω-tribromomethylpyrimidine,4-phenyl-6-ω,ω,ω-tribromomethylpyrimidine,2-ω,ω,ω-trichloromethyl-6-nitro-benzothiazole,1-phenyl-3-ω,ω,ω-trichloromethylpyrazole,ω,ω,ω-tribromolepidinebromomethylate,α-ω,ω-dibromomethyl-4-chloro-pyridine,1-methyl-2-(chloromethyl)-benzoimidazole,2,5-ditribromomethyl-3,4-dibromothiophene and the like.

As still another photo activator, there are the compounds represented bythe formula (V): ##STR3## (wherein X¹, X² and X³ each independently is agroup selected from hydrogen, chlorine and bromine, but all thereofcannot be hydrogens at the same time, and R represents a substituted orunsubstituted aryl, hetero residue), and specific examples of suchcompounds may include hexabromodimethyl sulfoxide, pentabromodimethylsulfoxide, hexabromodimethyl sulfone, trichloromethylphenyl sulfone,tribromomethylphenyl sulfone, trichloromethyl-p-chlorophenyl sulfone,tribromomethyl-p-nitrophenyl sulfone, 2-trichloromethylbenzothiazolesulfone, 4,6-dimethylpyridine-2-tribromomethyl sulfone,tetrabromodimethyl sulfone, 2,4-dichlorophenyltrichloromethyl sulfone,2-methyl-4-chlorophenyltrichloromethyl sulfone,2,5-dimethyl-4-chlorophenyltrichloromethyl sulfone,2,4-dichlorophenyltribromomethyl sulfone and the like.

The discoloring agent to be used in the present invention is a compoundwhich is discolored by the action of the free radical formed by thephoto activator under the influence of UV-rays, as described above, andsuch discoloring agents are also well known in this field of art. Thesediscoloring agents are inherently colorless substances, which arecolored by the action of the free radical, and those having inherentcolors which are discolored into another color by the action of the freeradical, or are decolored, and representative examples of these mayinclude, as examples of the former, amine compounds such asdiphenylamine, dibenzylamine, triphenylamine,N-hydroxyethyl-N-ethylaniline, p,p'-methylenebis(N,N-diethylaniline) andthe like, leucobases of the dyes such as leucocrystal violet,leucomalachite green, Michler's hydrol, fluoran compounds such as3-diethylamino-7-chlorofluoran, 3-methylamino-6-chlorofluoran,3-dimethylamino-6-methoxyfluoran, 3-cyclohexylamino-6-chlorofluoran,3-diethylaminobenzo(a)-fluoran, 3-diethylamino-6-aminofluoran,3,6-dimethoxyfluoran, 3-diethylamino-7-dibenzylaminofluoran,3-diethylamino-6-methyl-7-chlorofluoran and the like, polyarylalkanecompounds such as bis(4-diethylamino-2-methylphenyl)phenylmethane,tris(4-diethylamino-2-methylphenyl)methane,bis(4-dimethylamino-2-methoxyphenyl)phenylmethane,bis(4-diethylamino-2methylphenyl)(4-diethylaminophenyl)methane,bis(4-diethylamino-2-methylphenyl) (3,4-dimethoxyphenyl)methane,bis(4-dibenzylamino-2-methylphenyl)phenylmethane and the like,pyrazoline compound such as 1-phenyl-3-(p-diethylamino)styryl-5-(p-diethylamino)phenylpyrazoline and the like. On the otherhand, as the examples of the latter, various kinds of dyes such asdiphenylmethane type, triphenylmethane type, thiazine type, oxazinetype, xanthene type, anthraquinone type, iminonaphthoquinone type,azomethine type, etc., can be effectively used, and examples of thesemay include Auramine, Victoria Blue, benzoylmethylene blue,cinnamoylmethylene blue, rhodamine,4-p-diethylaminophenyliminonaphthoquinone,p-methoxybenzoyl-p-diethylamino-o-methylphenyliminoacetoanilide,1-phenyl-3-methyl-4-p-diethylaminophenylimino-5-pyrazolone and others.

Next, as the UV-ray absorber to be used in the UV-ray sensitivecomposition, there may be included any UV-ray absorber generallyemployed in the prior art, and specific examples thereof may include,for example, p-aminobenzoic acid derivatives (PABA derivatives),cinnamic acid derivatives, salicylic acid derivatives, camphorderivatives, benzophenone derivatives, urocanic acid derivatives,nitrogen containing heterocyclic derivatives, etc.

The UV-ray sensitive composition according to the present invention canbe used for the measurement of a UV-ray dose as described below bycoating on an appropriate support. As such supports, any material suchas paper, plastic film, glass plate, metal plate, etc., may be used, butit is preferable to use an paper base for photography, a plastic film,etc., to obtain sharp colors.

In the case of coating the UV-ray sensitive composition according to thepresent invention as described above on a support, an appropriatepolymeric binder having a film forming property, for example, cellulosederivatives such as ethyl cellulose, cellulose acetate, hydroxypropylcellulose, carboxymethyl cellulose sodium salt, etc., vinyl typepolymers such as polyvinyl chloride, polyvinyl acetate, etc., acrylicresins such as polyacrylate, polymethacrylate and copolymers of these,etc., coating resins such as silicone, alkyd, polyamide, linearpolyesters, solvent soluble type engineering plastics such aspolycarbonate, polyarlate, polysulfone, aromatic polyesters, copolymerssuch as ethylene-vinyl acetate copolymer, ethylene-acrylic acidcopolymer, etc., may be coated as a solution dissolved in a solvent(e.g. methanol, ethanol, isopropanol, benzene, toluene, xylene, ethylacetate, isobutyl acetate, acetone, 2-butanone, 4-methyl-2-pentanone,tetrahydrofuran, dioxane, methylene chloride, chloroform,1,1,1-trichloroethane, chlorobenzene, dimethylacetoamide, dimethylsulfoxide, N-methyl-2-pyrrolidone). In the UV-ray sensitive compositionof the present invention, pigments, plasticizers, etc., other than theessential components as mentioned above can be formulated if desired.

The element for the measurement of the UV-ray dose according to thepresent invention can be constituted by coating a layer 2 containing aphoto activator, a discoloring agent, and a UV-ray absorber on a support1 as shown in FIG. 1, and the element for the measurement of the UV-raydose can be protected by coating the surface thereof with a protectivelayer 3 of a transparent polymeric material having a film formingproperty (e.g. methyl cellulose, hydroxypropyl cellulose, polymethylacrylate, polyvinyl chloride) as shown in FIG. 2.

According to another embodiment of the element for measurement of aUV-raydose according to the present invention, as shown in FIG. 3 andFIG. 4, first a layer 4 containing a photo activator and a discoloringagent is applied on the support 1, and a layer 5 containing a UV-rayabsorber is applied thereon. Further, if necessary, a transparentprotective layer 3 as mentioned above can be coated thereon.

The amount ratios and coating amounts of the respective constituents ofthe UV-ray sensitive composition (or element for measurement of a UV-raydose) according to the present invention are not particularly limited,but a preferable example is shown below.

    ______________________________________                                        polymeric binder                                                                            100         parts by weight                                     Photo activator                                                                             0.1-100     parts by weight                                     Discoloring agent                                                                           0.1-200     parts by weight                                     UV-ray absorber                                                                             0.1-200     parts by weight                                     ______________________________________                                    

Also, the coating amounts of the respective layers are not particularlylimited, but are generally within the ratios as shown above, and it isdesirable to apply a coating at a solid component weight of 0.01 to 20g/m², preferably 1 to 10 g/m².

The thickness of the respective layers can be suitably selected, butgenerally the thickness of the support can be made 20 to 200 μm, and thelayers containing the photo activator, discoloring agent, and/or UV-rayabsorber be made 0.5 to 20 μm, and the protective layer be made 1 to 20μm.

The UV-ray sensitive composition of the present invention forms freeradicals from the photo activator corresponding to the irradiated dosewhen irradiated with UV-rays, and exhibits a conspicuously sharp changein color by acting on the discoloring agent. UV-ray sensitivecompositions known in the prior art undergo an immediate change in colorfrom an irradiation of light, within an extremely short time, and it isimpossible to measure the irradiated dose of light (particularlysunlight) by the change in color. In contrast, the UV-ray sensitivecomposition of the present invention, by controlling the amount of freeradicals generated from the photo activator during the irradiation ofUV-rays, by the addition of a UV-ray absorber in addition to the photoactivator and discoloring agent, the change in color is weakened, andthus a measurement of the irradiated dose of UV-rays is renderedpossible by the change in color.

Accordingly, by preparing previously the standards in change of theirradiated dose of UV-rays and color, a measurement of irradiated doseof UV-ray is easily possible without a particularly skilled technique,and by analysis of the color according to a spectrophotometer, theirradiated dose of UV-rays can be measured with a high precision.Further, the UV-ray sensitive composition of the present invention willnot bring about a change in coloration even after preservation for along time, when preserved under light shielding, thus having a specificfeature in that it can be satisfactorily provided for a measurement ofthe irradiated dose of UV-rays.

Also, even when exposed to various atmospheric conditions or solutions,so long as the photo activator, discoloring agent, and UV-ray absorberconstituting the UV-ray sensitive composition are not corroded thereby,the change in color is exhibited by an irradiation of UV-rays withoutany interference with the measurement of the irradiated dose. Further,the influence of the temperature on the coloration by UV-ray irradiationof this UV-ray sensitive composition is negligible at -20° to 60° C.,and in addition , the coloration after irradiation does notsubstantially change over a lapse of time after such coloration whenstored under light shielding, and therefore, an error such as thatcaused by a change with a lapse of time in measurement does not occur.Therefore, the UV-ray sensitive composition of the present invention canbe stored under light shielding for a certain period of time afterUV-ray irradiation, and again irradiated with UV-rays, whereby the totalirradiated dose of UV-rays can be measured.

EXAMPLES

The present invention is described in more detail by referring to thefollowing examples, but the present invention is not limited to theseExamples as a matter of course.

EXAMPLE 1

    ______________________________________                                        Solution I                                                                    Leucocrystal violet   1.0       g                                             Tetrabromodimethylsulfone                                                                           0.1       g                                             Ethylene-vinyl acetate copolymer                                                                    10        g                                             Toluene               100       ml                                            Solution II           2-Ethylhexyl N,N--dimethyl                                                              7 g                                           paraaminobenzoate                                                             Ethylene-vinyl acetate copolymer                                                                    10        g                                             Toluene               100       ml                                            ______________________________________                                    

The above solutions I and II were separately prepared, and first thesolution I was applied on a paper base for photography to 1 g/m² as thesolid component, and subsequently, the solution II was applied thereonto 5 g/m² as the solid component. The UV-ray sensitive composition thusobtained was exposed to sunlight, and the relationship between theirradiated dose of UV-ray and color was investigated. The irradiateddose of UV-rays was measured by a UV-ray irradiation dosemeter, and thecolor difference was calculated according to the LAB coordinate systemwith the color at the time of the irradiated dose=0 as the standard.

The results were as shown in Table 1.

                  TABLE 1                                                         ______________________________________                                                Irradiated            Color difference from                           Sample  dose.sup.(1)          the sample at irra-                             No.     [erg/cm.sup.2 ]                                                                           Hue       diated dose of 0.sup.(2)                        ______________________________________                                        1       0           White     0                                               2        500 × 10.sup.5                                                                     Pale violet                                                                             3.9                                             3        1000 × 10.sup.5                                                                    Pale violet                                                                             8.3                                             4        2000 × 10.sup.5                                                                    Pale violet                                                                             16.2                                            5        3000 × 10.sup.5                                                                    Pale violet                                                                             24.1                                            6        4000 × 10.sup.5                                                                    Pale violet                                                                             31.9                                            7        5000 × 10.sup.5                                                                    Violet    39.8                                            8        6000 × 10.sup.5                                                                    Violet    48.1                                            9        7000 × 10.sup.5                                                                    Violet    55.8                                            10       8000 × 10.sup.5                                                                    Violet    64.2                                            11       9000 × 10.sup.5                                                                    Dark violet                                                                             72.1                                            12      10000 × 10.sup.5                                                                    Dark violet                                                                             81.3                                            ______________________________________                                         .sup.(1) Produced by Suga Co., measured by UVray irradiation dosemeter.       .sup.(2) Measured by Hitachi 607 Spectrophotometer, and calculated            according to the LAB coordinate system.                                  

As is apparent from the results in Table 1, the UV-ray sensitivecomposition according to the present invention is, for example, whitebefore an irradiation of Uv-rays but the hue and the degree of colorthereof are changed as the irradiated dose is increased. The change inhue is mild, and the irradiated dose can be preparing previously thestandard in change of the irradiated dose of Uv-rays and the change incolor, an irradiated dose of 10000×10⁵ [erg/cm² ] corresponding to theirradiated dose of UV-rays in one day during midsummer could be easilymeasured without a skilled technique.

    ______________________________________                                        Solution I                                                                    Leucomethylene blue   1         g                                             α,α,α-Tribromoacetophenone                                                        0.5       g                                             Ethylene-vinyl acetate copolymer                                                                    10        g                                             Xylene                100       ml                                            Solution II                                                                   2-Hydroxy-4-methoxybenzophenone                                                                     5         g                                             Ethylene-vinyl acetate copolymer                                                                    10        g                                             Xylene                100       ml                                            ______________________________________                                    

The above solutions I and II were separately prepared, and the solutionI was first applied on a plastic film to 2 g/m² as the solid component,and subsequently the solution II to 6 g/m² as the solid component. TheUv-ray sensitive composition thus obtained was evaluated as in Example1.

The results were as shown in Table 2.

                  TABLE 2                                                         ______________________________________                                                Irradiated                                                            Sample  dose                                                                  No.     [erg/cm.sup.2 ]                                                                           Hue       Color difference                                ______________________________________                                        1       0           White     0                                               2        100 × 10.sup.5                                                                     Pale blue 3.0                                             3        200 × 10.sup.5                                                                     Pale blue 5.9                                             4        400 × 10.sup.5                                                                     Pale blue 12.1                                            5        600 × 10.sup.5                                                                     Pale blue 17.9                                            6        800 × 10.sup.5                                                                     Pale blue 23.8                                            7       1200 × 10.sup.5                                                                     Blue      36.1                                            8       1600 × 10.sup.5                                                                     Blue      49.3                                            9       2000 × 10.sup.5                                                                     Blue      60.3                                            10      2400 × 10.sup.5                                                                     Blue      70.0                                            11      3200 × 10.sup.5                                                                     Dark blue 78.3                                            12      4000 × 10.sup.5                                                                     Dark blue 85.7                                            ______________________________________                                    

As is apparent from the results in Table 2, also in his case theirradiated dose of UV-rays of 4000×10⁵ could be easily measured withouta skilled technique, as in Example 1.

EXAMPLE 3

    ______________________________________                                        Solution I                                                                    Leucomethylene green  1         g                                             Trichloromethylphenylsulfone                                                                        1         g                                             2-(2'-Hydroxy-5'-methylphenyl)benzotriazole                                                         5         g                                             Ethylene-vinyl acetate copolymer                                                                    10        g                                             Toluene               100       ml                                            ______________________________________                                    

The above solution I was prepared and applied on a paper base forphotography to 5 g/m² as the solid component. The UV-ray sensitivecomposition thus obtained was evaluated as in Example

The results were as shown in Table 3.

                  TABLE 3                                                         ______________________________________                                                Irradiated                                                            Sample  dose                                                                  No.     [erg/cm.sup.2 ]                                                                           Hue       Color difference                                ______________________________________                                        1       0           White     0                                               2        100 × 10.sup.5                                                                     Pale green                                                                              6.9                                             3        200 × 10.sup.5                                                                     Pale green                                                                              13.8                                            4        300 × 10.sup.5                                                                     Pale green                                                                              20.8                                            5        400 × 10.sup.5                                                                     Pale green                                                                              27.9                                            6        500 × 10.sup.5                                                                     Pale green                                                                              35.3                                            7        600 × 10.sup.5                                                                     Green     42.2                                            8        700 × 10.sup.5                                                                     Green     49.8                                            9        800 × 10.sup.5                                                                     Green     56.2                                            10      1000 × 10.sup.5                                                                     Green     65.0                                            11      1200 × 10.sup.5                                                                     Dark green                                                                              74.0                                            12      1400 × 10.sup.5                                                                     Dark green                                                                              82.3                                            ______________________________________                                    

As is apparent from the results in Table 3, also in this case theirradiated dose of UV-rays of 1400×10⁵ [erg/cm² ] could be easilymeasured without a skilled technique, as in Example 1.

EXAMPLE 4

    ______________________________________                                        Solution I                                                                    Leucomethylene blue      5        g                                           Trichloromethylphenylsulfone                                                                           5        g                                           Ethylene-vinyl acetate copolymer                                                                       10       g                                           Benzene                  100      ml                                          Solution II                                                                   2-Ethylhexyl N,N--dimethyl paraamino-4-methoxybenzophenone                                             5        g                                           Ethylene-vinyl acetate copolymer                                                                       10       g                                           Benzene                  100      ml                                          ______________________________________                                    

The above solutions I and II were separately prepared, and the solutionI was first applied on an original paper for photography to 4 g/m² asthe solid component, and subsequently, the solution 11 thereon to 4 g/m²as the solid component. The UV-ray sensitive composition thus obtainedwas investigated as in Example 1.

The results were as shown in Table 4.

                  TABLE 4                                                         ______________________________________                                                Irradiated                                                            Sample  dose                                                                  No.     [erg/cm.sup.2 ]                                                                           Hue       Color difference                                ______________________________________                                        1       0           White     0                                               2        50 × 10.sup.5                                                                      Pale blue 4.9                                             3       100 × 10.sup.5                                                                      Pale blue 10.0                                            4       150 × 10.sup.5                                                                      Pale blue 14.9                                            5       200 × 10.sup.5                                                                      Pale blue 20.1                                            6       150 × 10.sup.5                                                                      Pale blue 25.2                                            7       300 × 10.sup.5                                                                      Blue      30.2                                            8       400 × 10.sup.5                                                                      Blue      40.0                                            9       500 × 10.sup.5                                                                      Blue      49.8                                            10      600 × 10.sup.5                                                                      Blue      60.4                                            11      700 × 10.sup.5                                                                      Dark blue 70.1                                            12      800 × 10.sup.5                                                                      Dark blue 81.2                                            ______________________________________                                    

As is apparent from the results in Table 4, also in this case theirradiated dose of UV-rays of 800×10⁵ [erg/cm² ] could be easilymeasured without a skilled technique, as in Example 1.

EXAMPLE 5

    ______________________________________                                        Solution I                                                                    3-Diethylamino-benzo(a)-fluorane                                                                    5         g                                             Tribromomethylphenylsulfone                                                                         5         g                                             Linear polyester      10        g                                             2-Butanone            100       ml                                            Solution II                                                                   2-Hydroxy-4-methoxybenzophenone                                                                     5         g                                             Linear polyester      10        g                                             2-Butanone            100       ml                                            ______________________________________                                    

The above solutions I and II were separately prepared, and the solutionI was first applied on a plastic film to 2 g/m² as the solid component,and subsequently, the solution II to 5 g/m² thereon as the solidcomponent. The Uv-ray sensitive composition thus obtained was evaluatedas in Example 1.

The results were as shown in Table 5.

                  TABLE 5                                                         ______________________________________                                                Irradiated                                                            Sample  dose                                                                  No.     [erg/cm.sup.2 ]                                                                           Hue       Color difference                                ______________________________________                                        1       0           White     0                                               2        100 × 10.sup.5                                                                     Pale pink 6.0                                             3        200 × 10.sup.5                                                                     Pale pink 11.0                                            4        300 × 10.sup.5                                                                     Pale pink 15.5                                            5        400 × 10.sup.5                                                                     Pale pink 21.3                                            6        500 × 10.sup.5                                                                     Pink      27.4                                            7        750 × 10.sup.5                                                                     Pink      42.6                                            8       1000 × 10.sup.5                                                                     Pink      53.4                                            9       1500 × 10.sup.5                                                                     Dark pink 65.0                                            10      2000 × 10.sup.5                                                                     Dark pink 83.0                                            ______________________________________                                    

As is apparent from the results in Table 5, also in this case theirradiated dose of UV-rays of 2000×10⁵ [erg/cm² ] could be easilymeasured without a skilled technique, as in Example 1.

EXAMPLE 6

    ______________________________________                                        Solution I                                                                    Bis(4-diethylamino-2-methyphenyl)-                                                                  5         g                                             phenylmethane                                                                 Tribromomethylphenylsulfone                                                                         2.5       g                                             Polycarbonate         10        g                                             Methyl chloride       150       ml                                            Solution II                                                                   2-Hydroxy-4-methoxybenzophenone                                                                     5         g                                             Polycarbonate         10        g                                             Methyl chloride       150       ml                                            ______________________________________                                    

The above solutions I and II were separately prepared, and the solutionI was first applied on a plastic film to 5 g/m² as the solid component,and subsequently, the solution II to 2g/m² thereon as the solidcomponent. The UV-ray sensitive composition thus obtained was evaluatedas in Example 1.

The results were as shown in Table 6.

                  TABLE 6                                                         ______________________________________                                              Irradiated                                                              Sample                                                                              dose                                                                    No.   [erg/cm.sup.2 ]                                                                             Hue       Color difference                                ______________________________________                                        1      0            White     0                                               2      25           Pale green                                                                              7.2                                             3      50           Pale green                                                                              13.6                                            4      75           Pale green                                                                              19.0                                            5     100           Pale green                                                                              25.0                                            6     150           Green     35.1                                            7     200           Green     42.9                                            8     250           Green     54.6                                            9     300           Green     65.1                                            10    350           Dark green                                                                              77.3                                            11    400           Dark green                                                                              83.0                                            ______________________________________                                    

As is apparent from the results in Table 6, also in this case theirradiated dose of UV-rays of 400×10⁵ [erg/cm² ] could be easilymeasured without a skilled technique, as in Example 1.

EFFECT OF THE INVENTION

As described above, since the UV-ray sensitive composition of thepresent invention undergoes a color change corresponding to the UV-rayirradiated dose, the irradiated dose of UV-rays can be measuredextremely easily without requiring a skilled technique. Accordingly, thecomposition of the present invention can be used suitably as the elementfor measurement of a UV-ray irradiated dose as described above, and canbe applied as printed matter (e.g., a poster) which is changed in colorby UV-rays, and further, the above element for measuring the dose ofUV-rays can be utilized as a medical aid for patients hypersensitive tosunlight, by which the patients hypersensitive to sunlight can easilydetermine the dose of UV-rays to which they have been exposed,semiquantitatively, an implement for simply measuring the UV-rayprotective function of cosmetics, or as an implement for measuring theexposed amount of UV-rays at living level and attached to a badge,pendant, bracelet, watch, earring, spectacles, hair pin, hair band, etc.

We claim:
 1. A UV-ray sensitive composition, comprising a photoactivator forming a free radical by irradiation of UV-rays, adiscoloring agent which exhibits a color change in visible region ofspectrum through the action of this free radical, and a UV-ray absorberfor controlling the amount of free radicals generated.
 2. An element formeasuring a UV-ray dose, comprising a UV-ray sensitive compositioncomprising a photo activator forming a free radical by irradiation ofUV-rays, a discoloring agent which exhibits a color change in visibleregion of spectrum through the action of this free radical, and a UV-rayabsorber layered on a support for controlling the amount of freeradicals generated.
 3. An element for measurement of a UV-ray dosecomprising a first layer comprising a photo activator forming a freeradical by irradiation of UV-rays and a discoloring agent exhibiting acolor change in visible region of spectrum by the action of this freeradical, and a second layer comprising a UV-ray absorber layered on asupport for controlling the amount of free radicals generated.
 4. Acomposition according to claim 1, wherein the photo activator isselected from the group consisting of ##STR4## in which R is allyl,alkyl, aralkyl, aroyl, alkenyl, halogen or hydrogen,X is halogen, R_(x)is form 1 to 5 substituents independently selected from nitro, halogen,alkyl, haloalkyl, acetyl, haloacetyl, alkaryl and alkoxy, R₁ isoptionally substituted allyl or alkyl, A is an optionally substitutedheterocyclic radical, R₁, R₂ and R₃ each independently is hydrogen,chlorine or bromine but all three are not simultaneously hydrogen, R₂ isan optionally substituted aryl or heterocyclic radical, and X¹, X² andX³ each independently is hydrogen, chlorine or bromine.
 5. A compositionaccording to claim 1, wherein the discoloring agent is selected from thegroup consisting of diphenylamine, dibenzylamine, triphenylamine,N-hydroxyethyl-N-ethylaniline, p,p'-methylenebis(N-N-diethylaniline),leucocrystal violet, leucomalachite green, Michler's hydrol,3-diethylamino-7-chlorofluoran, 3-methylamino-6-chlorofluran,3-dimethylamino-6-methoxyfluoran, 3-cyclohexylamino-6-chlorofluroan,3-diethylaminobenzo (a)-fluran, 3-diethylamino-6-aminofluoran,3,6-dimethoxyfluran, 3-diethylamino-7-dibenzyl-aminofluoran,3,6-dimethoxyfluoran, 3-diethylamino-7-dibenzylaminofluoran,3-diethylamino-6-methyl-7-chlorofluoran, bis(4-diethylamino-2-methylphenyl)phenylmethane,tris(4-diethylamino-2-methylphenyl)methane,bis(4-diethylamino-2-methylphenyl)(4-diethylaminophneyl)methane,bis(4-diethylamino-2-methylphenyl) (3-4-dimethoxyphenyl) methane,bis(4-dibenzylamino-2-methylphenyl) phenylmethane,1-phenyl-3-(p-diethylamino)styryl-5-(p-diethylamino) phenylpyrazoline,Auramine, Victoria Blue, benzoylmethylene blue, cinnamoylmethylene blue,rhodamine, 4-p-diethylaminophenyliminonaphthoquinone,p-methoxybenzoyl-p-diethylamino-o-methylphenyliminoacetoanilide and1-phenyl-3-methyl-4-diethylaminophenylimino-5-pyrazolone.
 6. Acomposition according to claim 1, wherein the UV-ray absorber isselected from the group consisting of a derivative of p-aminobenzoicacid, cinnamic acid, salicylic acid, camphor, benzophenone, urocanicacid and a nitrogen containing heterocyclic.